How to change main class intellij. To create the standard Java main method, type main.

How to change main class intellij report. If you are not familiar with Maven at all, you can read about its basic concepts such as POM, build lifecycle Aug 13, 2016 · Like in Eclipse, when we create the new class, there is the option to add Static void main line, the same way, how can I add this to IntelliJ Java CE whenever create the new class? I'm trying to package a project using OptaPlanner 6. Did you configure an SDK in IntelliJ? Jul 24, 2025 · IntelliJ IDEA provides first-class support for Kotlin. I hope it will help somebody out there! I found two possibilities to create working JAR files under IntelliJ 2017. idea folder and re-add your How To rename things in IntelliJ: 1) Renaming a file when renaming a file we have to follow a rule of class names and file names in java must be the same if we change one, the other must match Go to File > Project Structure > Artifacts, check the necessary class files are included and the correct main class is set. I usually input command line arguments in Eclipse via run configuration. , `java -cp . Most of the Java tools are available for Kotlin, so, for example, if you know how to use Java debugger or refactorings, your experience will be enough to use these in Kotlin. Mar 4, 2013 · I have a class that appears as undefined in the IDEA ide. Jun 6, 2017 · You can change the assignments using File / Settings / Keymap then Main Menu / Navigate find Back and Forward and right click to Add Keyboard Shortcut to set an alternative key chord. 0 Main- Oct 8, 2024 · Use this dialog to rename a class or an interface. out. Maven is a build automation and project management tool primarily used for Java. You can save temporary run configurations, change their settings, share them with other members of your team. 2 1. Dec 13, 2017 · 15 I am trying to create a run configuration for a spring boot app, but Intellij can't find the main class of the spring boot app (Usually it is automatically populated). In the Live Templates section, expand the Java group on the left. As opposed to viewing static figures, live data may help you to visualize resource consumption, identify resource-related bottlenecks, and understand how certain events affect the program performance. Click Next to apply suggestions. Take the time to familiarize yourself with the project structure outlined in the IDE’s configuration settings. Solutions Verify that your main application class contains the `@SpringBootApplication` annotation and is located in the correct package. That director folder will change color from yellow to blue; IntelliJ considers all those directories to be in your CLASSPATH. Here's its answer: In IntelliJ IDEA, you can turn off the automatic generation of System. Feb 19, 2018 · In Eclipse, when I type main ctr + space, it will generate a static void main method for me. The usages are grouped into categories that correspond to options you can enable or disable. In IntelliJ, go to Run -> Edit Configurations and make sure your Spring Boot main class is correctly specified under 'Main class'. Here are the steps to refactor a class, method, or package in IntelliJ IDEA: Refactoring a Class Rename a Class: In the editor or the Project tool window, right-click and select the class name Nov 11, 2024 · When you clicked Run, IntelliJ IDEA created a temporary run configuration named after the Main class. java after making the configuration and decides to run three. IntelliJ IDEA will display the Change Signature inlay hint in the editor. Jun 14, 2022 · Intellij launch error: Could not find main class com/intellij/idea/Main Asked 7 years, 4 months ago Modified 2 years, 9 months ago Viewed 9k times Feb 16, 2017 · I created new project, new class (Main. When you compile Kotlin to Java bytecode, even if you have a plain "script" file, it gets turned into a Java class because that's what the JVM needs. I make Minecraft mods using Intellij with Java 8, and ive always not known how to rename everything without fucking everything… Aug 9, 2024 · Now whenever I start the application, it pops up with an error message saying: Could not find main class com/intellij/idea/Main I don't want to reinstall the IDE. You can set up a scope for Learn how to effectively rename a top-level package in IntelliJ IDEA, including tips and code snippets for successful refactoring. Wait for IntelliJ IDEA to restart with the new runtime. mf containing the standard Manifest-Version: 1. Setting the classpath in IntelliJ IDEA is essential for your Java applications to locate the necessary classes and resources. b. I'm trying to add a directory to the classpath of an application run profile If I override by using -cp x:target/classes in the VM settings, I get the following error: java. (This class is normally auto-generated by intelliJ after creating a new project). g. By default, the main class name is cucumber. Creating an artifact from IntelliJ: Go to project structure: Create a new artifact: Select the main class, and be sure to change the manifest folder: You have to change manifest directory: Jan 28, 2025 · Change signature in place  In the editor, start adding or editing the parameter of a class or a method. These refactorings are useful when a class has grown too large and "does too many things". Solution: Ensure that the output directory is specified in 'File > Project Structure'. Currently, when he creates a new proje Oct 11, 2024 · Open the needed file in the editor and go to Build | Recompile 'class name' (Ctrl Shift F9) in the main menu. java, he has to go to edit configurations and change the main class method. Apr 5, 2017 · a. Invalidating caches forces IntelliJ to rebuild its internal data. IntelliJ IDEA displays a live template that you can use to generate the full code construct and save a lot of time. java) and must write " public static void main(String[] args){} " It will be good if will possible generation main method by IDE. You can also use ⌘J (macOS) / Ctrl+J (Windows/Linux) to see all the Live Templates in IntelliJ IDEA that are valid for the current context. Sep 11, 2025 · IntelliJ IDEA is a professional IDE focused on ergonomic keyboard usage. Select + at the top left hand corner. 3)"Build" menu -> " Rebuild May 19, 2025 · Select a method or a class that you want to refactor. In the Settings window, navigate to Editor > Live Templates. How to How do I make a main class in IntelliJ? To create a new class, press ⌘N on MacOS or Alt+Insert on Windows or Linux on the directory in the Project Window, and select “Java class”. Otherwise, go to File | New Project in the main menu. On the main or context menu, select Refactor | Make Static. In the run configuration dialogue, you can see the run configuration that IntelliJ IDEA automatically created for running the main method in our HelloWorld. If found, the changes that you make to the class or the interface name can also be applied to these usages. He asks how can he set up some template so creating a new project will contain a default main class. println ("Hello World") in a few simple steps: Open your project in IntelliJ IDEA. But I don't know how do achieve the same task in IntelliJ IDEA. Mar 18, 2025 · When you use IntelliJ IDEA to create and run your simple files, you could run it like any other executable class (saves you from specifying the compilation or run time command line parameters that you must use otherwise). May 15, 2025 · Use the Rename refactoring in IntelliJ IDEA to easily change the names of various symbols and update all references to them in your code. Name the project (for example HelloWorld) and Learn how to troubleshoot and fix the 'Cannot run Main class' issue in IntelliJ IDEA with our expert guide and detailed solutions. Sep 6, 2019 · When creating a run configuration in Intellij, only a few of the modules in my project are offered as options. Main: Do not forget to specify the package where your Nov 8, 2018 · A class file is just a compiled Java source file, so if the latter has a main method, then the former should have one too. Select a code fragment that you want to extract into a class. Oct 3, 2019 · This problem happens to me frequently, then I did a lot of research. Oct 15, 2025 · IntelliJ IDEA provides the following ways to create a permanent run/debug configuration: When there is an executable class or method, you can create a permanent run/debug configuration right from the editor. java then it runs two's main, but if I run three. It will save you from common pitfalls and enhance your overall development experience. Alternatively, in the Project tool window, right-click the class you need and from the context menu, select Recompile 'class name'. Launch IntelliJ IDEA. This should work! Learn how to select and run a main class in IntelliJ IDEA when encountering errors with class visibility and source roots. In addition, I cannot select the Application class I want to use. In such cases, it may be a good idea to split the class into smaller, more cohesive classes. If the Welcome screen opens, click New Project. Invalidate Caches and Restart IntelliJ IntelliJ caches project data to speed up performance, but corrupted caches can cause weird issues like "main class not found. For more information, refer to Run/debug configurations. jar through IntelliJ IDEA's jar artifact but instead of my manifest. Firstly, we can simply run Ctrl + Shift +F10 or Control + Shift + R/D from the main class. e. In the main menu, go to File > Settings. Program Arguments Values entered here are passed into the String[] parameter of your main method when the program begins. Learn how to master shortcuts and include them in your workflow to maximize productivity. Jul 23, 2024 · As you know, code refactoring is one of the most advantageous actions in programming and IntelliJ IDEA provides many opportunities to improve your code’s readability, maintainability, and structure. " Why this happens: Caches may become outdated if you rename files, move packages, or update dependencies. domain. Try running the JAR file directly from the command line using java -jar YourApp. When I select Refactor → Rename on package com. jetbrains. You can right click on any directory in your IntelliJ project, select "Mark Directory As", and choose "Source Root". After this, proceed to refactor and rename the class that contains the main method to match your new project name. Aug 16, 2024 · IntelliJ IDEA lets you use refactorings that extract fields, methods, and parameters into a new class. It defines the entry point and the parameters for running the application. To create the standard Java main method, type main. In the New Project wizard, select Java from the list on the left. Sep 23, 2017 · Not all the time would want the main class file to be Main, often times you would want to change the main class file like illustrated in the gif, so every time I would have to specify which class file is the main class file. cli. reporting. 1 libraries into a . Solution: Double-check the path in the run configuration and ensure it matches your Java class. Change the name to “Main” d. In the dialog that opens, specify the refactoring options. 113 Intellij allows you to specify two types of arguments when running a Java program: VM Options Enables you to modify attributes of the JVM, including stack/heap memory allocation, system properties, GC flags, etc. In this tutorial a simple Java project will be used. Mistake: Project output directory not set, leading to class files not being generated. If errors occur during the compilation process, IntelliJ IDEA will display them in the Review compilation and build output along with warning messages. I have tried switching between Project view and Package, but to no avail. So I used Alt-Enter and accidentally chose the wrong path/location for the class. So that the JVM doesn't have to guess, you must tell it which class contains the main method that you want to run. According to JetBrains, the creator of IntelliJ: Use the Rename refactoring to change names of symbols, files, directories, packages, modules and all the references to them throughout code. Create from a template or copy an existing configuration. It includes Kotlin-specific project templates, coding assistance, refactorings, debugging, analysis tools, and so on. And when I type methodName ctr + space, smart code completion will suggest generating the method named methodName. Ensure your project is built correctly. When you open the Choose Boot Runtime for the IDE dialog for the first time, it may take a while to load the list of JetBrains Runtime builds from the server. In addition to renaming the class or the interface itself, IntelliJ IDEA can also search for usages of its name. Mistake: Incorrect main class path specified in the IntelliJ configuration. model, I only see an option to rename 'model'. Feb 27, 2009 · A friend is just starting to learn Java, using IntelliJ. In summary, you need to: Mark your src directory as “Sources Root” Cancel your src’s exclusion Delete your . And you should see the build icon (Hammer). Feb 15, 2008 · How could I add some directories to the existing classpath of a junit configuration? I cannot at -cp to the VM parameters because it will override the existing classpath . If you miss setting the language level to 24, IntelliJ IDEA can detect that and prompt you to do so (as shown below): In IDEs such as Eclipse or IntelliJ IDEA, you can configure the run settings to specify the main class. Select it. For a class, if the class references any outer class fields, IntelliJ IDEA suggests passing the outer class as a parameter to the inner class constructor. model. Eventually, I find out the way to solve it. Nov 10, 2017 · Provided that cucumber support is enabled you should be able to run the test from . You should now see your Main Class. Let's create a new configuration for running our new JAR file. If you are editing a parameter, IntelliJ IDEA will offer to update the usages for you. java class. Aug 8, 2024 · Now, there are 2 approaches for running this main method in IntelliJ. Select “Application” c. When running from the command line, use the `-cp` option with Java to point to the main class directly, e. Click the inlay hint or press Alt Enter. If friend Nihar runs two. Jun 28, 2017 · I have a Java project and I want to modify it in intellij but I can't do it because of this " read-only file " or "file is not writable" , so how I can modify and execute it? This is still an issue in 2017. Mar 25, 2025 · Run tests using the Run widget  When you run a test, IntelliJ IDEA creates a temporary run configuration. 2) "Run" menu -> " Edit configuration " -> delete the profile -> add back the profile ("Application" if it's a Java application), choose your main class from the "Main Class" dropdown menu. You should now see the execute arrow at that top right of Intellij. . Jul 1, 2025 · Last modified: 01 July 2025 In this tutorial you will learn how to add a Maven support to an existing IntelliJ IDEA project and build it using Maven. Aug 27, 2025 · In IntelliJ IDEA, a project helps you organize your source code, tests, libraries that you use, build instructions, and your personal settings in a single unit. When creating a new class, we can type the whole package path, separated by dots, followed by the class name, and IntelliJ IDEA will create the package and the Java file. Idea doesn't see my main class when I try to configure Artifact here's my Gradle : plugins { id 'java' id 'org. You can do that by pressing + (macOS) / Plus (Windows/Linux) and select JAR Application from the list. The problem is that when I look at the configurations, I cannot find the src folder in it nor choose my main class from the list neither. Jul 25, 2020 · Is there a way to disable auto-generation of the main class (class containing main method) when I create a new project in IntelliJ? Apr 16, 2018 · Learn how to configure your Spring Boot application's main class in Maven and Gradle. Refactor Rename Quickly renaming classes, methods, and variables in IntelliJ IDEA. Jul 30, 2025 · IntelliJ IDEA provides a way to monitor live performance statistics for a running process through CPU and Memory Live Charts. Now click on the Ellipsis (three dots) in “Main Class”. How do I change this to point/refer to a different path?T Jan 25, 2017 · For mine, if I run from my class two. jar to see if both IntelliJ and the command line produce errors. NoClassDefFoundEr Dec 17, 2019 · I try to build a jar with Intellij Idea with Kotlin Gradle project. I know how to make this change in Eclipse via Navigator view, but how can I do the same in IntelliJ IDEA? May 18, 2012 · Sometimes Intellij doesn't rewrite the classes because they already exist, this way you ask Intellij to rewrite everything. How can I auto-generate a void method in IntelliJ? 35 votes, 11 comments. I tried adding the class by searching the project structure, but Intellij won't let me add that application's main file to 'Main class' of the configuration. Create a new run configuration or save a temporary one. 0. Feb 17, 2025 · If necessary, you can change the location where IntelliJ IDEA will download the selected runtime. For a method, if the method references any of the containing class Learn how to fix IntelliJ IDEA running outdated class files with step-by-step guidance and code examples. This guide walks you through the process of configuring the classpath for an application launched from IntelliJ IDEA, ensuring smooth execution of your project. Nov 8, 2025 · 7. When trying to sele Aug 6, 2021 · You can right click the name of the variable/function and select refactoring > rename. feature file's context menu: Also in Run/Debug configurations window -> Cucumber java -> what should be the main class? The class is taken from the jar archive attached when enabling Cucumber support in project. Jun 4, 2024 · By ensuring that IntelliJ recognizes these folders correctly, you can mitigate most problems related to selecting a main class. You can also use a shortcut for this which is depending on your configuration (default being Shift + F6). In Java, every single class could choose to define its own main method. lang. May 26, 2017 · I would like to change it to com. java it runs three's main. Save a temporary run/debug configuration as permanent. wap ljgzy mnkkd nwe mabfvz pjb gtw rhhy eyr lwu hyvewv ycvunc snw phjn fcdu